Bats are known to provide many ecological services and to serve as ecological indicators. However, with bat populations declining in North America due to habitat loss and invasive diseases, we wanted to know how species richness in bats varies through time. We made use of a published report from Pierson and Rainey in 2017 that detailed bat acoustic surveys from 2001 through 2006 in Sequoia and Kings Canyon National Park. Our ongoing work in 2019 includes four acoustic recorders spread throughout Sequoia and Kings Canyon National Park. We paired our 2019 data with data from 2001-2006 at matching locations that were within 10 kilometers, 250 meters elevation, as well as similar habitat type to assess temporal changes from 2001-2006 to 2019. We measured past and present species richness at each site as well as compared species guilds based on their foraging strategy in different forest structures (open-adapted, clutter-adapted, or edge-adapted).
Results/Conclusions
We observed mixed results; one site had significantly higher species richness in 2019 than in 2001-2006, three sites showed decreases in richness but only one of those three sites with decreases in richness were statistically significant. However, across all sites the net change of our species guilds was a loss in 3 open-adapted, a gain of 3 cluttered-adapted, and a gain of 8 edge-adapted bat species. Thus, while the number of species may be comparable, the types of species present in 2019 are not the same as the types of species present in 2001-2006. The loss of species that inhabit open-forests and the gain of species that inhabit edge habitat and cluttered forests suggests species guild shifts consistent with fire suppression.